Air-stable ambipolar organic field effect transistors with heterojunction of pentacene and N,N'-bis(4-trifluoromethylben-zyl) perylene-3,4,9,10-tetracarboxylic diimide

Fabrication of ambipolar organic field-effect transistors （OFETs） is essential for the achievement of an organic complementary logic circuit. Ambipolar transports in OFETs with heterojunction structures are realized.We select pentacene as a P-type material and N,N＇-bis（4-trifluoromethylben-zyl）perylene-3,4,9,10-tetracarboxylic diimide （PTCDI-TFB） as a n-type material in the active layer of the OFETs.The field-effect transistor shows highly air-stable ambipolar characteristics with a field-effect hole mobility of 0.18 cm^2/（V·s） and field-effect electron mobility of 0.031 cm^2/（V·s）.Furthermore the mobility only slightly decreases after being exposed to air and remains stable even for exposure to air for more than 60 days.The high electron affinity of PTCDI-TFB and the octadecyltrichlorosilane （OTS） self-assembly monolayer between the SiO2 gate dielectric and the organic active layer result in the observed air-stable characteristics of OFETs with high mobility.The results demonstrate that using the OTS as a modified gate insulator layer and using high electron affinity semiconductor materials are two effective methods to fabricate OFETs with air-stable characteristics and high mobility.

An air-stable and waterproof lithium metal anode enabled by wax composite packaging

The reviving use of lithium metal anode(LMA)is one of the most promising ways to upgrade the energy density of lithium ion batteries.In the roadmap towards the real use,besides the formation of the dendrite,various adverse reactions due to the high activity of LMA when exposed to air or the electrolyte limit its practical applications.Learning from the packaging technology in electronic industry,we propose a wax-based coating compositing with the ion conducting poly(ethylene oxide)by a simple dip-coating technology and the prepared LMA is featured with an air-stable and waterproof surface.The LMA thus remains stable for 24 h in ambient air even with the relative humidity of 70% while retaining about85% its electrochemical capacity.More importantly,the LMA is accessible to water and when dipping in water,no obvious adverse reactions or capacity decay is observed.With the composite coating,a steady cycling performance for 500 h in symmetrical cells and a low capacity decay rate of 0.075% per cycle after 300 cycles in lithium-sulfur batteries assembled with the packaged anode have been achieved.This work demonstrates a very simple and effective LMA package technology which is easily scalable and is very promising for speeding up the industrialization of lithium-sulfur batteries and shows potentials for the large-scale production of air-sensitive electrode materials not limited to LMAs.

Air-stable n-type transistors based on assembled aligned carbon nanotube arrays and their application in complementary metal-oxide-semiconductor electronics

Carbon nanotubes(CNTs)are ideal candidates for beyond-silicon nano-electronics because of their high mobility and low-cost processing.Recently,assembled massively aligned CNTs have emerged as an important platform for semiconductor electronics.However,realizing sophisticated complementary nano-electronics has been challenging due to the p-type nature of carbon nanotubes in air.Fabrication of n-type behavior field effect transistors(FETs)based on assembled aligned CNT arrays is needed for advanced CNT electronics.Here in this paper,we report a scalable process to make n-type behavior FETs based on assembled aligned CNT arrays.Air-stable and high-performance n-type behavior CNT FETs are achieved with high yield by combining the atomic layer deposition dielectric and metal contact engineering.We also systematically studied the contribution of metal contacts and atomic layer deposition passivation in determining the transistor polarity.Based on these experimental results,we report the successful demonstration of complementary metal-oxide-semiconductor inverters with good performance,which paves the way for realizing the promising future of carbon nanotube nano-electronics.

High-mobility air-stable n-type field-effect transistors based on large-area solution-processed organic single- crystal arrays

Solution-processed n-type organic semiconductor micro/nanocrystals （OSMCs） are fundamental elements for developing low-cost, large-area, and all organic logic/complementary circuits. However, the development of air-stable, highly aligned n-channel OSMC arrays for realizing high-performance devices lags far behind their p-channel counterparts. Herein, we present a simple one-step slope-coating method for the large-scale, solution-processed fabrication of highly aligned, air-stable, n-channel ribbon-shaped single-crystalline N,N＇-bis（2- phenylethyl）-perylene-3,4：9,10-tetracarboxylic diimide （BPE-PTCDI） arrays. The slope and pattemed photoresist （PR） stripes on the substrate are found to be crucial for the formation of large-area submicron ribbon arrays. The width and thickness of the BPE-PTCDI submicron ribbons can be finely tuned by controlling the solution concentration as well as the slope angle. The resulting BPE-PTCDI submicron ribbon arrays possess an optimum electron mobility up to 2.67 cm2.V-l.s-1 （with an average mobility of 1.13 cm2.V-l-s-1）, which is remarkably higher than that of thin film counterparts and better than the performance reported previously for single-crystalline BPE-PTCDI-based devices. Moreover, the devices exhibit robust air stability and remain stable after exposing in air over 50 days. Our study facilitates the development of air-stable, n-channel organic field-effect transistors （OFETs） and paves the way towards the fabrication of high-performance, organic single crystal-based integrated circuits.

An air-stable ultrahigh-mobility two-dimensional Bi_2O_2Se semiconductor

Subject Code:B03 With the support of the National Natural Science Foundation of China,the research team led by Prof.Peng Hailin(彭海琳)from Peking University,reported recently on the discovery of an air-stable twodimensional Bi2O2Se semiconductor with ultrahigh electron mobility,which was published in

Dual-doping for enhancing chemical stability of functional anionic units in sulfide for high-performance all-solid-state lithium batteries

The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herein,we proposed an Al and O dual-doped strategy for Li_(3)PS_(4)SE to regulate the chemical/electrochemical stability of anionic PS_(4)^(3-)tetrahedra to mitigate structural hydrolysis and parasitic reactions at the SE/Li interface.The optimized Li_(3.08)A_(10.04)P_(0.96)S_(3.92)O_(0.08)SE presents the highestσLi+of 3.27 mS cm^(-1),which is~6.8 times higher than the pristine Li_(3)PS_(4)and excellently inhibits the structural hydrolysis for~25 min@25%humidity at RT.DFT calculations confirmed that the enhanced chemical stability was revealed to the intrinsically stable entities,e.g.,POS33-units.Moreover,Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE cycled stably in Li//Li symmetric cell over 1000 h@0.1 mA cm^(-2)/0.1 mA h cm^(-2),could be revealed to Li-Al alloy and Li_(2)Oat SE/Li interface impeding the growth of Li-dendrites during cycling.Resultantly,LNO@LCO/Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)/Li-In cell delivered initial discharge capacities of 129.8 mA h g^(-1)and 83.74%capacity retention over 300 cycles@0.2 C at RT.Moreover,the Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE presented>90%capacity retention over 200 and 300 cycles when the cell was tested with LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)cathode material vs.5 and 10 mg cm^(-2)@RT.

A bifunctional ethylene-vinyl acetate copolymer protective layer for dendrites-free lithium metal anodes

Lithium metal batteries are strongly considered as one of the most promising candidates for nextgeneration high-performance battery systems.However,the uncontrollable growth of lithium dendrites and the highly reactive lithium metal result in the severe safety risks and the short lifespan for highenergy-density rechargeable batteries.Here,we demonstrate a hydrophobic and ionically conductive ethylene-vinyl acetate(EVA)copolymer layer can not only endow lithium metal anodes with an air-stable and anti-water surface,but also efficiently suppress the lithium-dendrites growth during the electrochemical cycling process.Therefore,the introduction of the EVA copolymer as a bifunctional protection layer simultaneously improves the anti-water/air performance and electrochemical cycling stability of lithium metal anode.

Enhanced hydrogen generation from hydrolysis of MgLi doped with expanded graphite

Hydrolysis of Mg-based materials is considered as a potential means of safe and convenient real-time control of H_(2)release,enabling efficient loading,discharge and utilization of hydrogen in portable electronic devices.At present work,the hydrogen generation properties of MgLi-graphite composites were evaluated for the first time.The MgLi-graphite composites with different doping amounts of expanded graphite(abbreviated as EG hereinafter)were synthesized through ball milling and the hydrogen behaviors of the composites were investigated in chloride solutions.Among the above doping systems,the 10 wt.%EG-doped MgLi exhibited the best hydrogen performance in MgCl_(2)solutions.In particular,the 22 h-milled MgLi-10 wt.%EG composites possessed both desirable hydrogen conversion and rapid reaction kinetics,delivering a hydrogen yield of 966 mL H_(2)g^(-1)within merely 2 min and a maximum hydrogen generation rate of 1147 mL H_(2)min^(-1)g^(-1),as opposed to the sluggish kinetics in the EG-free composites.Moreover,the EG-doped MgLi showed superior air-stable ability even under a 75 RH%ambient atmosphere.For example,the 22 h-milled MgLi-10 wt.%EG composites held a fuel conversion of 89%after air exposure for 72 h,rendering it an advantage for Mg-based materials to safely store and transfer in practical applications.The similar favorable hydrogen performance of MgLi-EG composites in(simulate)seawater may shed light on future development of hydrogen generation technologies.

单分子结中的有机自由基

空气稳定有机自由基的发现引起了人们对探究其在分子电子学和自旋电子学中应用的兴趣.这些自由基具有独特的开壳层电子结构,因而表现出特殊的电学特性.由于其较弱的旋轨耦合特性,也使得其成为自旋电子学的重要研究对象.此外,自由基还可以通过二聚、分子识别和机械互锁等分子间相互作用来构筑超分子器件.本文综述了空气稳定有机自由基在电子学及自旋电子学中的应用,通过详述其卓越的电磁性能来拓展启发分子设计的多样性.本综述还概述了超分子自由基的制备方法和相关性质的研究进展,拓宽了单分子研究的范围.此外,自由基介导的单分子反应是一个新兴的研究方向,本文也对该领域的未来发展方向进行了展望.通过阐明空气稳定有机自由基的应用潜力,本文将有望对分子电子学和自旋电子学的研究产生一定的指导意义.